STUDIES OF PH ZONE REFINING COUNTERCURRENT CHROMATOGRAPHY

手性拆分(/-)-二硝基苯甲酰(DNB)氨基酸的研究 在分析性和预备性两个方面都成功地执行了 使用手性选择剂(CS)，N-十二酰-L-脯氨酸- 3，5-二甲基苯胺。分离是分两个阶段进行的 正己烷/乙酸乙酯/甲醇/10 mMHCl组成的溶剂体系 (8：2：5：5)在有机固定相中加入适量的CS 相位。样品大小可达2g，分离时间为2-7小时。 考察了影响手性拆分的各种参数。 使用一组DNB-氨基酸外消旋体。结果表明， 增加固定相中CS的浓度可改善 分离因子(α)和峰值分辨率(Rs)。增加了 溶剂体系的疏水性也增加了α 消旋体，但它对峰分辨率的影响不同，根据 外消旋体的分配系数。我们的结果表明， 最佳分离将通过施加较高的CS浓度来实现 以及调节溶剂体系的疏水性，以使 (K)外消旋体的分配系数在0.6~0.8之间。 对手性分离进行了简单的数学分析，结果令人满意 与实验数据吻合较好。

Chiral separation of (+/-)-dinitrobenzoyl(DNB) amino acids was successfully performed in both analytical and preparative scales by high-speed CCC, using a chiral selector (CS), N-dodecanoyl-L-proline- 3,5-dimethylanilide. The separations were carried out with a two-phase solvent system composed of hexane/ethyl acetate/ methanol/10mM HCl (8:2:5:5) by adding a proper amount of the CS in the organic stationary phase. The sample size ranging up to 2g was separated in 2-7 hours. Various parameters involved in the chiral resolution were investigated using a set of DNB-amino acid racemates. The results indicated that increasing the concentration of the CS in the stationary phase improves both separation factor (alpha) and peak resolution (Rs). Increasing the hydrophobicity of the solvent system also increased the alpha of the racemate while it affected the peak resolution differently according to the partition coefficient of the racemate. Our results indicated that the best separation will be achieved by applying a high CS concentration and adjusting the hydrophobicity of the solvent system so that the partition coefficient of (K) the racemates falls between 0.6 and 0.8. A simple mathematical analysis on the chiral separation shows good agreement with the experimental data.